#include<stdio.h>
//打印1-100之间所有3的倍数
int main()
{
	int i = 0;
	for (i = 3;i <= 100;i += 3)
		printf("%d ", i);
	return 0;
}

//将三个整数数按从大到小输出
int main()
{
	int a = 0, b = 0, c = 0;
	scanf_s("%d%d%d", &a, &b, &c);
	if (a >= b && b >= c) printf("%d %d %d", a, b, c);
	else if (a >= c && c >= b) printf("%d %d %d", a, c, b);
	else if (b >= a && a >= c) printf("%d %d %d", b, a, c);
	else if (b >= c && c >= a) printf("%d %d %d", b, c, a);
	else if (c >= a && a >= b) printf("%d %d %d", c, a, b);
	else if (c >= b && b >= a) printf("%d %d %d", c, b, a);
	return 0;
}

//三角形判断
int main() {
    int a, b, c;
    while (scanf_s("%d %d %d", &a, &b, &c) != EOF) {
        if (a + b > c && a + c > b && b + c > a)
        {
            if (a == b && b == c)
                printf("Equilateral triangle!\n");
            else if (a == b || a == c || b == c)
                printf("Isosceles triangle!\n");
            else printf("Ordinary triangle!\n");
        }
        else printf("Not a triangle!");
    }
    return 0;
}

//计算1/1-1/2+1/3-1/4+1/5 …… + 1/99 - 1/100 的值
int main()
{
	double sum = 0;
	for (int i = 1;i <= 100;i++)
	{
		double a = 1.0 / i;
		if (i % 2 == 0)
			sum -= a;
		else sum += a;
	}
	printf("%f", sum);
	return 0;
}

//1到100的所有整数中出现多少个数字9
int main()
{
	int count = 0;
	for (int i = 1;i <= 100;i++)
		if (i % 10 == 9 || i / 10 == 9)
		{
			printf("%d ", i);
			count++;
		}
	printf("\n");
	printf("1到100的所有整数中出现%d个数字9\n", count);
	return 0;
}

//打印1000年到2000年之间的闰年
int main()
{
	for (int i = 1000;i <= 2000;i++)
	{
		if (i % 4 == 0 && i % 100 != 0) //四年一闰百年不闰
			printf("%d ", i);
		else if (i % 400 == 0)  //每四百年再一闰
			printf("%d ", i);
	}
	return 0;
}

//求10个整数中最大值
int main()
{
	int a[10] = { 0 };
	int max = 0;
	for (int i = 0;i < 10;i++)
		scanf_s("%d", &a[i]);
	  for (int i = 0;i < 10;i++)
	  {
		if (a[i] > max)
			max = a[i];
	  }
	printf("%d", max);
	return 0;
} 